These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Amino acid exchange between plasma and erythrocytes in vivo in humans.
    Author: Darmaun D, Froguel P, Rongier M, Robert JJ.
    Journal: J Appl Physiol (1985); 1989 Dec; 67(6):2383-8. PubMed ID: 2606845.
    Abstract:
    To study amino acid exchange between plasma and erythrocytes in vivo, 4-h primed, continuous intravenous infusions of L-[1-13C]leucine, [15N]glycine, and L-[15N]alanine were administered to five healthy young men in the postabsorptive state. Stable isotope enrichments and amino acid levels were determined by gas chromatography-mass spectrometry in both plasma and whole blood and estimated (using hematocrit) in erythrocytes. A high concentration gradient across the erythrocyte membrane was consistently found for glycine (552 +/- 268 microM in erythrocytes vs. 155 +/- 35 microM in plasma), but not for leucine or alanine. A steady-state isotopic enrichment was observed in whole blood as well as plasma for each amino acid in every subject. Steady-state [13C]leucine enrichment in erythrocytes did not differ from plasma enrichment at steady state, the ratio of erythrocyte to plasma enrichment being 1.03 +/- 0.20 (95% confidence limits = 0.78-1.28); in contrast, this ratio reached only 0.23 +/- 0.04 and 0.59 +/- 0.09 (confidence limits 0.18-0.28 and 0.48-0.70) for [15N]glycine and [15N]alanine at steady state, respectively. These results suggest that most of erythrocyte leucine is exchangeable with plasma, whereas only a fraction of erythrocyte glycine and alanine is involved in exchange with plasma in vivo.
    [Abstract] [Full Text] [Related] [New Search]